New Post: (very) Basic Databinding question

You shouldn't really create a second copy of the window that you already have. You should instead reference the window by name.

<Window x:Name="MyWindow">
    <Grid DataContext="{Binding ElementName=MyWindow}">
...
    </Grid>
</Window>

You can also enable tracesources that allow you to see what WPF is doing with the binding, see: Trace sources in WPF and How to debug WPF bindings (You will want the Trace Level – new in 3.5 section)

Note 1: I have written this by hand so it might not be 100% actually.

Note 2: You should also read up on WPF because it sounds like this is your first real dive into it. At first, it's going to seem a LOT different to WinForms or ASP.NET if you've done those. But, in time, it does become easier and I actually prefer to use it these days.

These sites should help you:
Welcome to the WPF Tutorial
The complete WPF tutorial
WPF Tutorial : Beginning
Walkthrough: Getting Started with WPF